T S 

250 

Oh 



i 

i 



XXth Century 
Sheet Metal Worker 



H, E, OS3SOJUME 



THE AMERICAN ARTiSAN 

C H r C A C O 

1 D1 fa 



:^ 



W* 




1 

i 

Mi 



m 



EiiSlilSliiaiffllMIBiaBiSBIllSil 




No. 27 

Full L 
Lonptl 



Class 
Book. 




x^'ZJ O 




COPYRIGHT DEPOSIT. 



11 

9' ' 

i' 2i" 



LOO each 



/ S.&H.CO. V 



N.Y. U.S.A. 



(finmltiHatiou 

DROP FORQED STEEL. HANDY TINNERS' SNIPS. 

This Snip is adapted for cornice makers and is an all around 
combination tool, cutting circular, straiKli# and irregular shapes. 

No. 274 "Red Devil" 1" 18 19 110 

Full Length 14" 13" 12" 11 

Length or Cut ~.^L r~^-2K'' -2!!—- ^ 

PriccTjKSOeach Price, $ 1 .00 eacli 
Cash with order 

SMITH & HEMENVVAY CO. 

108=110 Duane Street, NEW YORK CITY 



Send for Sample Copy of 

THE AMERICAN ARTISAN 

AND HARDWARE RECORD 
THE TINNERS HELPER AND FRIEND 

We know you will be interested and want to show 
you how very valuable a trade journal can be. 

Practical Tinshop conducted by expert tinners 
who "know" from experience. Don't worry about a 
job that does not work out properly — let our Tinshop 
Department show you how to do it — that's how we 
demonstrate our value to you. 

Notes and Queries — a storehouse of valuable 
information tells where to buy wares and materials of 
all kinds, or if you have only the brand name, can put 
you in touch with the manufacturer of any tool or machine. 

You want RELIABLE information about the metal 
market, to know all about the newest patents and inven- 
tions, — in fact all the news and doings of the Sheet 
Metal World, and each issue of 

THE AMERICAN ARTISAN 

AND HARDWARE RECORD 

gives it. 

Send for Free Sample Copy and Special Offer To-day. 

THE AMERICAN ARTISAN 
AND HARDWARE RECORD 

DANIEL STERN, Publisher and Proprietor 

$2.00 per year, 52 Issues 

355 Dearborn Street - - CHICAGO, ILL. 



Warm Air Furnaces 

OF THE HIGHEST CLASS 

Established Reputation for RELIABILITY, 
ECONOMY and GENERAL EFFICIENCY 

The Fault- 
less Scienti- 
fic Heater is 
the acme of 
furnace con- 
struction. 

Furnace 
experts ac- 
knowledge 
its superior- 
ity- 
It will take 
the lead in 
all cases. 

Our General Line of Furnaces is Unsurpassed. 

HARD OR SOFT COAL 
HEAVY and MEDIUM WEIGHT 




SEND FOR CATALOGUE 



L 



THE GRAFF FURNACE CO. 

208 WATER STREET, NEW YORK 



XXth Century 
Sheet Metal W^jrker 



A Modern Treatise on Modern 
Sheet Metal Work 



BY 

H. E. OSBORNE 



THE AMERICAN ARTISAN 

CHICAGO 

1910 



^0 



Entered according to Act of Congress in the Year 1908 

by 

H. E. Osborne 

In the Office of the Librarian of Congress 

at Washington, D. C. 



CCI.A27S675 



TO 
MY OLD TIME TEACHER 

AND FRIEND 

GRIFFETH L. JACKSON 

THIS LITTLE BOOK 

IS 

AFFECTIONATELY 

DEDICATED 



PREFACE 

"Waste no time worrying over a mistake, but try 
to correct it to the best of your ability, with as httle 
loss of time and material as possible." — G. L. 
Jackson. 

And if this book shall prove to be of as- much help 
to just one struggling' "tinker" as the above quotation 
from my old teacher has been to me. then the time 
spent in its preparation has been well spent. 

I have endeavored to give in this work short, con- 
cise explanations, which should be easily understood 
by the young apprentice, and at the same time, suffi- 
ciently scientific for the practical use of the journey- 
man. Some of the items are of so simple a character 
as to seem to be almost unnecessary, but I have re- 
membered that even the most simple things have to be 
learned. 

H. E. Osborne. 



XXth Century 
Sheet Metal Worker. 



Having; a e^^^ii circle, to find the Bide of an equivalent square. 

Multiply the diameter by the decimal .8862, or, mul- 
tiply the circumference by the decimal .2821. Either 
method gives the length of one side of an equivalent 
square. 

Having a gk'oi circle, to find tJic side of an in- 
scribed square. 

Multiply the diameter by the decimal .7071, or, mul- 
tiply the circumference by the deciuidl .2251. 

The first method may also be applied to find the 




length of the chord of an arc of 90 degrees, a quad- 
rant. Find the radius and multiply it by 2 and then 



2 XXTH CENTURY SHEET METAL WORKER. 

by .7071. Because the side of an inscribed square is 
the chord of the quadrant. 

To i)iscribe a square in a circle. 

Draw the two diameters BD and AC at right angles 
to each other, and connect the extremities of the dia- 
meters by straight lines drawn from A to B, B to C, 
etc. 

To find the radius of an arc. 

To the square of the sine AC, add the square of the 




versed sine CD, and divide the result by twice the 
versed sine. 

To make this plain, and dispense with the geomet- 
rical terms. Square the length from A to C, and add 




to it the square of the distance C to D and divide the 



XXTH CENTURY SHEET METAL WORKER. 3 
result by twice C D. The quotient will be the length 
of radius to produce the arc ABD. 

To and the center from ivhich a given arc is pro- 
duced. 

Draw any two chords AB and CD, and bisect them, 
and from the points thus found draw lines perpendi- 
cular to the chords, and extending until they meet. 
The point of meeting will be the center of the circle 
of which the arc is a portion. 

To describe a circle cutting any three points, ar- 
ranged in any position other than a straight line. 




Connect the points by straight lines; then lines 
drawn perpendicular from the centers of these lines 
will meet at the center of the required circle. 

To find the length of an arc, zvhen the number of de- 
grees it contains and the radius are knozvn. 

Multiply the number of degrees by the decimal 
.01745, and that product by the radius. 

To find the area of a sector zvhen the number of de- 
grees and radius arc knoion. 



4 XXTH CENTURY SHEET METAL WORKER. 

Find the length of the arc by the preceding rule, and 
multiply this length by one-half the radius. 

To find the area of an oral or ellipse. 

Multiply the two axes together, and their product 
by the decimal .7854 and the result will be the required 
area. 

To find th« area of a clroalar ring. 

1st. When the circumference and diameter are 
both known, multiply the circumference by one-half 
the radius (one-fourth the diameter), or multiply one- 
half the circumference by one-half the diameter. 

2d. When the diameter only is known, square the 
diameter and multiply by the decimal .7854. 

To find the area of a circular ring. 

The space between two circles of unequal size., and 




having a common center. Square the diameter of each 
circle, and subtract the square of the lesser from the 
square of the greater, and multiply the difference by 
the decimal .7854. 



XXTH CKNTURY SHEET METAL WORKER. 
To inscribe an equilateral triangle in a circle. 




With any point (as A) as center, and radius equal 
to radius of the circle, describe arc cutting the circum- 
ference in B and then in C. Then bisect the arc B D 
C, and connect the points B, C, and D. 

To inscribe a hexagon in a circle. 




Describe the eciuilateral triangle as before. Then 



XXTH CENTURY SHEET METAL WORKER. 

bisect the arc C D in F, and the arc B D in G, and 
drew AC, CF, FD, DG, GB, and BA. 

Or it may be inscribed by applying the radius six 
times around the circumference. This is the most 
common method. 

To inscribe a regular pentagon in a circle. 

Draw the diameters AP and MN at right angles to 
each other, and bisect the radius ON at E. From A 




N 



as center, and EA as radius, describe the arc SB. Join 
the points A and B, and the hne AB being applied 
five times around the circle will form the pentagon. 

To draiv squares rvhose areas shall be proportionate 
to the areas of given squares. 

Fig. I. To draw a square % the area of a given 
square. Bisect one side of the given square, and con- 
struct a square upon half its length. 

Fig. 2. To draw a square J/2 the area of a given 
square. Draw diagonal lines from corner to corner 



XXTH CENTURY SHEET METAL WORKER. 





Fig, !• Fig. 2, 

of the given square, and construct a square upon 
half the length of one of the diagonals. 

Fig. 3. To draw a square twice the area of a given 




Fig. 3. 

square. Draw a diagonal line from corner to corner 
of the square, and construct a square upon the diag- 
onal. 

This is simply the reverse of Fig. 2. 

Fig. 4. To draw a square three times the area of 
a given square. Extend the side of the given square 
to a length equal to its diagonal, A to B, and from 



8 XXTll CENTURY SHEET METAL WORKER. 

the extremity of the extension, draw a hne to the op- 
posite corner of tiie square (B to C), upon which 
construct a square. 

Fig. I. To draw a square four times the area of a 
given square. Construct a square on a Vme twice the 




Fig. 4. 

length of one side tlie given square. 

Just the reverse of finding one of one-fourth the 
area. 

Fig. 5. To draw a square five times the area of a 
given square. Extend one side of the square to twice 
its original length, A to B, and from the extremity 
of the extension draw a line to the opposite corner 
of the square (B to C), upon which construct a 
square. 



XXTii CENTL'RV SllKliT METAL WORKER. 9 




Pig. 5. 

To describe an i\i:^g-sliapC(i oz'al. 

Describe a circle the size desired for the round 
end of the figure, and draw two diameters at right 
angles, as shown in cut. Then draw a straight line 
from each end of one of the diameters through the ex- 
tremity of the other diameter and extending indefi- 
nitely. With each enfl of the first diameter for center, 
and radius equal to the diameter, strike an arc from 
tlie opposite end of the diameter just to the diagonal 
line. Then with the intersection of the diagonal lines 
with the other diameter for center, and radius to just 



10 XXTH CENTURY SHEET METAL WORKER. 

meet the previous arcs, or side arcs, draw the small 
end arc, which completes the fig;urc. 




To draw an arc throngJi three points ■without locat- 
ing the center. 

Let A B and C be the points. Then with A and C 
as centers, and radius from A to C make arcs from 
A and C indefinitely towards D. Draw a straight line 




from A through B intersecting the arc C D at F. And 
another straight line from C through B intersecting 
the arc A D at G. 



XXTH CENTURY SHEET METAL WORKER. n 

Space the arcs between A and G. and between C and 
F into the same number of equal spaces, continuing 
one or two of the spaces beyond G and F towards D. 
Connect the points marked on A D with the point C, 
and the points marked on C D with the point A, and 
draw a freehand line through the intersections of these 
lines. 

To draiv any number of concentric circles, the area 
of each circular ring thus formed being equal to the 
area of each of the others and to the circle in the center. 

Draw a straight line A B. and space it into the num- 
ber of equal spaces desired. Bisect A B and draw 




upon it a semicircle, and draw a line perpendicular to 
A B from each of the points to the circumference of 



12 XXTH CENTURY SHEET METAL WORKER. 

the semicircle, as c, d, c, and f. Then with A as center 
and rachus A c describe the inner circle. The next 
with radius A d, &c., as shown in cut. 

To draw a line from a gircii point in a straight line, 
perpendicular to the gii'en line. 



B 



Let A be the given point, and R C the given line. 

Place one point of the dividers at A and set off B 
and C equal to each other. Tlien with B and C as 
centers, and with radius greater than A B, describe 
two arcs intersecting at D. Draw A D and it will be 
perpendicular to the line B C. 

Or, if the point A is near the end of the giz'en line. 

Place one foot of the dividers at anv reasonable 




point, as P. and extend the other foot to A. Then with 



XXTH CENTURY SHKET METAL WORKER. 13 

P as center and radius from P to A, describe a semi- 
circle, or a complete circle would be better, perhaps. 
Through C. where the circle cuts the line B A, and the 
point P, draw the line C P D. Then draw A D, and it 
will be perpendicular to the line B A. 

To draw from a i^ic'cii point outside a given straight 
line, a perpendicular to that line. 




Let A be the given point, and B D the given line. 
Then from the point A as a center, and with a radius 
greater than the distance from the line to A, describe 




14 XXTH CENTURY SHEET METAL WORKER. 

an arc cutting the line B D in the points B and D ; then 
mark the point E, equally distant from B and D, and 
draw A E, and it will be perpendicular to B D. 

Or if the point A is nearly opposite one end of the 
given line. 

Draw the line A C to any point on the line B D, as 
C. Bisect A C at F. Then with F as center, and F 
C or F A as radius, describe the semicircle C D A, and 
draw A D and it will be perpendicular to B D. 



Triangle 

2nd posi- 
tion. 



Triepi 
1st pQS 
tion. 




XXTH CENTURY SHEET METAL WORKER. 15 

To draiv a line to a gkrn p.oint, and pcrf^cndicidar 
to a i^h'cn line, iisini^ only a rule and trianij^le. 

Let AB be the given line, and C the given point. 

Place the long edge of the triangle against the rule 
v^ath the other long edge resting on the line AB. Then 
holding the rule firmly, slide the triangle along until 
the short side touches the point C. Then draw CD 
and it will be perpendicular to the line AB. 

Of course, only a right-angled triangle, as shown, 
can be used. 

With the same tools, to draiv a line to a given point, 
and parallel to a gii'en line. 



"" 'TrlangTe 

I 2nd position, jy 




i6 XXTH CENTURY SHEET METAL WORKER. 

Let C be the given point, and AB the given line. 

Place the rule and triangle the same as in the pre- 
vious example, and slide the triangle until the top 
edge just reaches the point C. Then draw a line along 
the top edge from C towards D, and it will be parallel 
to the line AB. 

To draiu a straight line equal to a given arc, an arc 
equal to a gii'en straight line, or an arc of different 
curvature equal to a gii'en arc. 



1^ 




Pig. 1. 



Space the given arc, Figure i, into 4 equal spaces 
by the intermediate points i, 2, 3. Draw AC tangent 
to the arc at A, and with A as center and radius A i 
mark D (the chord of yi the arcj. Then with D as 
center and radius D B strike the arc B E, and A K 
will be the same length as A B. 

Or, if the straight line be given, space it into 4 



XXTH CENTURY SHEET METAL WORKER. 17 

equal spaces, and with the first point of division D as 
center, strike the arc E B, and A B will equal A E. 

Also, let A B be the given arc, and A F an arc of 
unequal curvature. Space A B, as in the first proposi- 
tion, and set off D on the straight line tangent to both 
arcs at A, and with D as center and radius D B, draw 
the arc B to F. Then A F will equal A B. 

To develop, by the latter proposition, the pattern 
for the envelope of a cone, the slant height and size 
of base being known. 




Fig. 2. 



On any straight line, Fig. 2, set off the required 
slant height C D, and with D as center and radius 
C D, describe the indefinite arc X X. Set off from C, 



i8 XXTH CENTURY SHEET METAL WORKER. 

on line A B, the radius of the desired base C to E, 
and with E as center describe the complete circle. 
Draw a radius E F perpendicular to A B and space 
the quarter circle into 4 equal spaces. Erect a per- 
pendicular at C which will be tangent to the circle 
and to the long arc at that point, and on it set off 
one of the 4 equal spaces of the quarter circle, marked 
o. With o as center and radius o F describe the arc 
from F to the long arc at G. Then C G equals C F, 
or % the circumference of the base. 

Now span the dividers from C to G, and step this 
distance from G to H, and two steps from C to I, and 
connect H and I with D. Allow edges for lock and 
pattern is complete. 

The Octagon. 

To lay off an octagon ziithout a circle, or a cfttier, 
and with no internal lines whatever. 

Use the steel square, and after drawing a line the 
length desired for one side of the octagon, place the 
square on the line at 12 and 12, or 6 and 6, or any 
convenient numbers, using the same figure on the 
blade as on the tongue, and with one of these num- 
bers just at the end of the line, draw the next side 
along the blade of the square. Continue this process, 
being caYeful to make the sides exactly the same length, 
and to place the square so that the line last drawn 
crosses it just at the figures selected. 

The accompanying cut fully shows the manner of 
using the square. Here A B is the first side drawn, 
say 14 inches long, and the square is then placed on 
A B as shown, with 8 and 8 on the line and the edge 
of the blade (long side) at the end B of the line. Then 



XXTH CENTURY SHEET METAL WORKER. 19 
draw B C 14 inches long, which would be just to 22 on 
the blade. Swing the square around onto B C as 
shown bv the dotted outline and draw the next side. 



' ' V S. 

B ■/ / -V ^v. 



k<- 





The Octagon, 



If the work is done accurately the resulting figure 
will be a perfect octagon. 

In the cut the square is shown a little off from the 
line B C in order to show that line. But if the square 
was placed so that the 8 inch mark just coincides with 
end B of the line A B, then B C would just reach the 
22 inch mark on the blade. 

Of course anv size of octagon may be made in this 



20 XXTH CENTURY SHEET METAL WORKER. 

manner, by using smaller numbers on the square for 
drawing those with shorter sides. 



Diam. 


Area. 


Cir. 


Diam. 


Area. 


Cir. 


i 


0.0123 


.3927 


16 


201.06 


50.26 


i 


0.0491 


.7854 




213.82 


51.83 


1 


0.1104 


1.178 


17 


226.93 


53.40 


i 


0.1963 


1.571 




240.53 


54.98 


f 


0.3068 


1.963 


18 


254.47 


56.65 


i 


0.4418 


2.356 




268.80 


58.12 


i 


0.6013 


2.741 


19 


283 . 53 


59.69 


I 


0.7854 


3.142 




29S . 65 


61.26 


i 


O.9940 


3.534 


20 


314.16 


62.83 


i 


1.227 


3.927 




330.06 


64 . 40 


i 


1.485 


4.319 


21 


346.36 


65.97 


it 


1.767 


4.712 




363.05 


67.54 


i 


2.074 


5.105 


22 


380.13 


69.11 


i 


2.405 


5.498 




397.61 


70.68 


i 


2.761 


5.890 


23 


415.48 


72.25 


2 


3.142 


6.283 




433.73 


73.83 


i 


3.976 


7.068 


24 


452 . 39 


75.40 


^ 


4.909 


7.854 




471.43 


76.97 


i 


5.939 


8.639 


25 


490 . 87 


78.54 


3 


7.068 


9.425 


26 


530 . 93 


81.68 


i 


S.29^ 


10.21 


27 


572.56 


84.82 


i 


9.621 


10.99 


28 • 


615.75 


87. 9P 


i 


11.044 
12.566 


11.78 


29 


660.52 


91.10 


4 


12.56 


30 


706 . 86 


94.25 


i 


15.904 


14.14 


31 


754 . 77 


97.39 


5 


19.635 


15.71 


32 


804 . 25 


100.5 


i 


23.758 


17.27 


33 


855 . 30 


103.6 


6 


28.274 


18.85 


34 


907.92 


106.8 


i 


32,183 


20.42 


35 


962 U 


109.9 


7 


38.484 


21.99 


36 


1017.9 


113,1 


i 


44.179 


23.56 


37 


1075.2 


116.2 


S 


50 . 265 


25.13 


38 


1134.1 


119.4 


i 


56.745 


26.70 


39 


1194.6 


122.5. 


9 


63.617 


28.27 


40 


1256.6 


125.6 


A 


70.882 


29.84 


41 


1320.2 


128.8 


i6 


78.54 


31.41 


42 


1385.4 


131.9 


i 


86.59 


32.98 


43 


1452.2 


135.1 


11 


95.03 


34.55 


44. 


1520.5 


138.2 


i^ 


103.87 


36.13 


45 


1590.4 


141.4 


12 


113.10 


37.70 


46 


1661.9 


144.5 


• i 


122.72 


39.27 


47 


1734.9 


147.6 


13 


132.73 


40.84 


48 


1809.6 


150.8 


* 


143.14 


42.41 


49 


1885.7 


153.9 


14 


153.94 


43.98 


50 


1963.5 


157.1 


if 


165.13 


45.55 


51 


2042.8 


160.2 


15' 


176.71 


47.12 


52 


2123.7 


163.3 


^ 


188.69 


48.69 


53 


2206.2 


166.5 



XXTH CENTURY SHEET METAL WORKER. 21 
Diameters and Circumferences of Circles. 

To find the circumference of any circle greater than 
any given in the table, multiply by 2, 3, 4, 10 or any 
number of times. For instance : 

The circumference of 28 is 2 times that of 14. And 
the circumference of 140 is 10 times that of 14. The 
circumference of 14 is 43.98. and to find the circum- 
ference of 140 multiply 43.98 by 10. which is done by 
removing the decimal point one place to the right, 
making 439.8. 
A Short Method of Finding Circumferences Without Figures 

Draw a line 12 inches long, as A B in Fig. i. Span 
dividers to 3 13/16 inches, and with one point at B 




strike an arc C D. Set ofi' on this arc from C, the 
given diameter, as C E or C F. Then draw from B 
through E or F, another line 12 inches long, and the 



22 XXTH CENTURY SHEET METAL WORKER. 

distance from A to G will be the circumference of 
the diameter C E, or from A to H will be the circum- 
ference of the diameter C F. 

This rule is good for all small circles up to yy^ 
inches diameter which, being just 2 times 3 13/16, 

12" 




would make the arc C D a complete semi-circle, and 
the line B G would be swung around to form a con- 
tinuation of A B. thus making the distance from A to 
G 24 inches, which is just a little more than the true 
circumference of 7^, which is 23.955. 

A very convenient way of applying this method is 



XXTH CENTURY SHEET METAL WORKER. 23 
to mark across both legs of a two-foot folding rule, 
3 13/16 inches from the center c f the rivet in the mid- 
dle joint, which would be at 8 3/16 on one leg, and at 
15 13/16 on the other. Then by opening the two end 
joints of the rule and spreading the legs so that the 
marked points at the inside edges will be just the dis- 
tance apart of the given diameter, the inside corners 
will be the distance apart equal to the required cir- 
cumference. 

Fig. 2 shows the application of the rule to the same 
principle. B is the hinged joint, and the lines from 
B to 12" are the inside edges of the legs of the rule. 
It is here shown spread to 3>^ inches diameter, and 
measures 11 inches circumference. 

Some Remarkable Facts About Circles. 

We are taught from our > outh up, that the diameter 
of a circle multiplied by 3.1416 equals the circumfer- 
ence, and that the square of the diameter multiplied 
by .7854 equals the area. Some of the following facts, 
however, have not been so generally taught: 

That the diameter divided by .3183 equals the cir- 
cumference. 

That the circumference multiplied by .3183 equals 
the diameter. 

That one-half the circumference multiplied by one- 
half the diameter equals the area. And that the square 
of the circumference multiplied by .07958 equals the 
area. 

That the area of a circle is greater than that of an) 
other plain figure bounded by an outline of equal 
length. 

That in any circle whose diameter is less than 4 



24 XXTH CENTURY SHEET METAL WORKER, 
the area is less than the circumference ; i. e., the num- 
ber of square units of area is less than the number of 
lineal units of the circumference. 

That if the diameter is 4 the circumference and 
area are represented by the same number, each being 
12.5664, while in all circles whose diameters are more 
than 4 the areas exceed the circumferences, and the 
proportions of one to the other advance by a regular 
ratio, or progression, as will be seen by the following 
table: 

Diameter. Table. 

.1 area equals circnm. divided by 40. 
.4 area equals circum. divided by 10. 
.5 area equals circum. divided by 8. 

1 area equals circum. divided by 4. 

2 area equals circum. divided by 2. 

3 area equals circum. divided by i^. 

4 area equals circum.. 

5 area equals circum. multiplied by l54- 

6 area equals circum. multiplied by ij^. 

7 area equals circum. multiplied by i^. 

8 area equals circum. multiplied by 2. 
10 area equals circum. multiplied by 2^. 
12 area equals circum. multiplied by 3. 
14 area equals circum. multiplied by 3^. 
16 area equals circum. multiplied by 4. 
18 area equals circum. multiplied by 4^2. 
20 area equals circum. multiplied by 5. 
24 area equals circum. multiplied by 6. 
28 area equals circum. multiplied by 7. 
32 area equals circum. multiplied by 8. 
36 area equals circum. multiplied by g. 
40 area equals circum. multiplied by 10. 
44 area equals circum. multiplied by 11. 
48 area equals circum. multiplied by 12. 



XXTH CENTURY SHEET METAL WORKER. 25 
To use the table: Find the circumference by ref- 
erence to the table of diameters and circumferences 
given in another chapter, or by any rule, and divide or 
multiply by the number given in this table opposite 
the chosen diameter. For example: Diam. 2, the 
circum. of which is 6.2832, which divide by 2 and the 
area is found to be 3.1416. Again, diam. 12, circum. 
of which is 37.6991, which this table shows is to be 
multiphed by 3. 37-6991 X3=ii3-0973- the required 
area. 

The ratio of increase of the multipliers continues 
the same indefinitely, increasing ,^ for each unit of 
increase of diameter, so that this table may be used 
for finding the area of circles of other diameters than 
those given. If the diameter is 9 multiply the circum. 
by ^Ya. If 49 multiply by 12^4. If 50. by I2>4. H 
51, by 12^, and if 52, by 13. The multiplier con- 
tinuing to increase one unit for each 4 units of di- 
ameter. Hence, to find the area of a circle whose 
diam. is 400, multiply the circumference by 100. Thus, 
diam. 400, circum. 1256.64X100=125664. 

In other words, multiply the circumference by one- 
fourth the diameter to find the area of any circle. 
Scale of Hundredths. 
It frequently happens in making particularly accur- 
ate measurements that it is desired to measure a cer- 
tain number of hundredths of an inch. And some- 
times the required number is such that considerable 
time, and much figuring would be necessary, to re- 
duce it to a common fraction. 

A scale of hundredths is a great convenience in 



26 XXTH CENTURY SHEET METAL WORKER. 

such cases, and if the shop square does not contain 
one, it may be made very accurately, by any one, with 
a few minutes careful work. 




Near one end of a strip of tin, lay off a square inch, 
and space horizontally into ten equal spaces by paral- 
lel lines, and it is a good plan to continue these lines 
several inches along the tin. 

Space it the other way into equal spaces, and draw 
parallel lines having a slant of one space. That is, 
draw the first line from one corner of the square to 
the first space mark on opposite side, thus forming e 
triangle with one inch perpendicular, and one-tenth 
inch base. Draw the remainder of the lines exactly 
parallel to the first, and you will have a similar tri- 
angle at the opposite side only reversed. 

To use the scale extend dividers the required num- 
ber of whole inches and place both points on the re- 
quired line, .01, .02, etc., according to the number of 
hundredths to be added, with one point exactly on line 
A B. Then hold the other point firmly and extend 
the one resting on line A B to the intersection of the 
diagonal line with the one on which the dividers rest. 



XXTH CENTURY SHEET METAL WORKER. 2- 

For example, to find 2.06", extend the dividers two 
inches, and place one point on the intersection of the 
line .06 with the line A B, and holding the other point 
on line .06, extend the point on A B to the intersection 
of the first diasfonal line. 




With this scale any number of hundredths may be 
readily found. To find 1.99" extend dividers from 
X to X. Or for 1.92, from v to v, etc. 



28 XXTH CENTURY SHEET METAL WORKER. 
Measuring Degrees on the Steel Square. 

It sometimes happens that it is desirable to find a 
certain number 'of degrees when there is no protractor 
at hand. In such cases the steel square and the fol- 
lowing table will be found to answer the purpose with 
a reasonable degree of accuracy. 

Table. 

No. I No. 2 

Inches. Deg. Deg. 

1-2 45 45 

lo i/i6 40 50 

8 13/32 ;. -35 55 

6 15/16 30 60 

5 19/32 25 65 

5 22'{. (,r/2 

AVs 20 70 

3 7/32 15 75 

2 3/32 10 80 

I 1/16 5 85 

o o 90 

EXPL.\N.\TI0N OF T.^BLE. 

A line drawn from 12" on the blade to 12" on the 
tongue is 45° to either edge of the square. And a 
line drawn from 12" on either edge to any number in 
the column of inches, on the other edge, will be, at 
the 12". the number of degrees indicated in the column 
of degrees marked "No. i." And where it intersects 
the outer edge of the other arm of the square, it will 
be the number of degrees indicated in the column 
marked "No. 2." 

As the cut shows, the angles given in column No. I 
of Degrees are those at C, and the ones given in 
column No. 2 are those between A and B. 



XXTII CF.NTURY SHI'.F.T METAT. WORKER. 29 
Chimney Tops. 

An article of very general use throughout the coun- 
try, and yet one which seems to be quite difficult for 
many tinners to quickly draw patterns for, is the gal- 
vanized iron chimney top base. Really this is a tran- 
sition piece, being an article hav a square or rec- 
tangular base, and round top. 

The pattern for this article may e so quickly drawn 
that it is better to lay it off on the sheet to be used, 
and if made in two pieces, one only need be drawn, 
and the other cut by it. 

For the purpose of explaining the process we will 
take definite dimensions, say I3"xi7" with 4* perpen- 
dicular base, and tapered to fit a f pipe, the height to 
be just what will cut from 30-inch iron. The seams to 
he in the middle of the narrow sides. 

At a distance of 17 inches from one end of the 
^ect scribe at right angles across it, a line, as A B, 
letting the line extend indefinitely to A on the floor 
or bench after reaching the edge of the iron. This 
line is the center "\t« t tl' c half pattein. Set off from 
center line at B W2 to E, and the same distance to 
F. Then with the square scribe up from F to D 4^*, 
and from E to C 4^^", and connect C and D. 

From the center line at K set off a little less than ^ 
the circumference of top each way to G and H. For 
7* pipe about 5 inches each way, making 10 inches for 
the chord G H. For other sizes of top use about the 
same proportion — 10 to 22, or 5 to 11 — which would 
be about 85^ for 6-inch pipe, and about 11^ for 8- 
inch. 



30 XXTH CENTURY SHEET METAL WORKER. 

Next place the blade of square at G and 6J/2 inches 
on the tongue at C, as shown in drawing, and scribe 
from G to I, and from I to C, then slide the square 
down 4^ inches, keeping the blade to the line G I, 
and mark from J to E 63/2 inches, and connect E and 




C. Continue the line J G to A where it intersects 
with the center line. Mark the other side the same 
from H around to D, etc., and continue the line from 
H to A. 



XXTH CENTURY SHKKT MI'TAL WORKER. 31 

With A as center and radius A G strike the arc G 
H. Tlien draw lines from D to H, and from D to K, 
also from C to G and C to K. Lay off the allowance 
for lock along- each edge as shown by dotted lines, and 
cut out. 

The top should be cut on the arc G K H so the 
bends can be the more easily made on the lines C K 
and D K. Notch in from F to D and from E to C, 
leaving an allowance to rivet. Mark the other half 
by this, being careful to prick the points K, C, and D. 
Fold the bottom edge y\ inch over flat, and then 
straight out, to make a good stiff edge at bottom. 




Fig. 1. 



32 XXTH CENTURY SHEET METAL WORKER. 

Now fold the edg^e locks, one out and the other in, 
the same as for stove pipe, and then brake over stake, 
or in the brake if you have one, on the lines G C, K C, 
H D and K D, forming about square at C and D, and 
running out to round at top end G K H. Lock the 
two halves together and groove down the seams, after 
which bend on lines I C, C D, etc., to bring the 4-inch 
base strip to perpendicular, and rivet the corners. 

Chimney Saddles. 

The chimney saddle is a very important article, and 
is much better than a plain flashing behind the chim- 
ney, because being sloped both ways, it allows the 
water to all run off quickly, while the flashing usually 
remains wet for some time, and soon rusts through. 




Fig. 2. 



Fig. I shows the saddle in place behind a chimney 
on a 1/3 pitch shingled roof. A, B, C, D and E being 
a side elevation. 

To develop the pattern, draw X X, Fig 2, the pitch 
of roof, A E the perpendicular line of chimney, B C 



XXTH CENTURY SHEET METAL WORKER. 33 

the width desired for high point of saddle, and E the 
width of ends at low point. 

Suppose, for example, the roof is 1/3 pitch, and the 
chimney is 26 inches wide, and the saddle to be 6 
inches wide at high point. Make B C. at right angles 
to A E, and 6 inches long. And E, i inch long, par- 
allel to B C. 

Next cut a piece of galvanized iron 16x28 inches 
and lay it off as shown in Fig. 3. A to B is 4 inches, 
[') to C 6 inches and C to D 6 inches. Cut straight in 
from A to B, and from D to C. Then bend at right 
angles on line E E, and to about 1/3 pitch on lines C 
E and C E. Bend at B C until the line B C is as high 




Pig. 3. 

above the ends at E as the distance B E in Fig. 2. 
Rest it on the bench in this position and solder a gore 
over the V-shaped opening A B. Turn the wide side 
E D E down flat on bench and solder a gore over the 
opening D C. These gores should also l)c riveted to 
prevent the solder breaking, and they should both be 



34 XXTII CENTURY SHEET .METAL WORKER. 

put on the inner side, as they will not leak quite so 
badlv in case the solder does become broken. 




Fig, 4, 

Fig. 4 shows the completed article with the riveted 
gores. 

Gutter and Gutter Aliters— Octagon and Half Round. 

In Figures i and 2 are shown square miter patterns 
for octagon and half round gutter, the inside and out- 
"^ide of miter of each, and each taking the same width 
of stock, in this case Q inches. 

In Fig. 1 the dimensions are as follows, tht^ugh these 



XXTIl CENTURY SHEET METAL WORKER. 35 
may be varied at will: o to i. I2 in.; i to 2. -ji in..; 
2 to 3, }i in. ; 3 to 4, i in. ; 4 to 5, i in. ; 5 to 6, 2/2 
in. ; 6 to 7, I in. ; 7 to 8, i>^ in. 

This takes jnst inches width of stock, and is a 




Pig. 1. 

very convenient size of gutter to make, as a 3()-inch 
sheet of iron will cut 4 pieces without waste. 

To develop the pattern, draw profile as shown, then 
draw a stretch-out 9 inches from o to 8, and any de- 
sired len.Qth. Space the stretch-out 0123. etc.. the 
same measurements as o i 2 3, etc., in profile. Draw 



36 XXTH CENTURY SHEET METAL WORKER. 

lines from the points of bend in profile to intersect 
the space lines in stretch-out as shown, and connect 
these intersections by straight lines. 

Cut on the miter line, and prick both end? of each 



piece on the space lines, ai 
complete, by which any nu 



d the two patterns are 
nber of pieces may be 




marked and pricked for bending. In cutting out by 
these patterns one piece of each pair should be cut a 
half inch longer and notched in at each point of bend, 
to form a lap, as a much stronger job is made by so 
doing, than by butting them together. 

For marking the long pieces which are to have no 



XXTH CENTURY SHEET METAL WORKER. i7 
miters cut on them, a narrow strip of iron may be 
prick marked i 2 3, etc., and cut 9 inches long. Prick 
each end of the piece by this pattern, and it is then 
ready to form up in the brake. 

In forming up, put the 0123 edge of piece into 
the brake to the third dot (dot 3). Bend square up. 
Reverse and put the same edge in, the other side up, 
to dot 2, and bend square up. Pull back to dot i, 
and also bend square, this finishes the bead. Turn it 
around and put in to dot 4, and bend up to 45°, pull 
back to 5 and bend to 45°, then 6 and 7 each 45°. 

It is a good plan to cut a. stay the exact shape of 
profile, and form the gutter to the shape of the stay, 
as nearly as possible. 

In Fig. 2 is shown a very similar development of 
the half round gutter miter. The bead pattern is a 
complete two-piece elbow pattern, and the half round 
part is just half of an elbow pattern, and each part 
may be laid out by any method of elbow with which 
the workman is familiar. 

The bead in Fig. 2 is shown somewhat out of pro* 
portion, but the principle of development is the sami 
regardless of the size. 

Box Gutter. 

I used to dread a job of box gutter. It seemed to be 
a hard matter for me to put it in properly, and not 
spend too much time on the job. 

For the benefit of others who may be troubled in 
the same manner, I will describe my present method. 
And, by the way, I rather like the work. 

We will suppose we have a box gutter job which is 



38 XXTH CENTURY SHEET METAL WORKER. 

to finish over the edge of crown mould with a bead, 
which is a common style of finish at the present time. 
Make up the bead in 28-inch lengths (or in 20-inch 
if you have only a 20-inch header in the shop), and of 
sufficient width to cover the flat or slightly sloped sur- 
face between the gutter and outer edge of cornice, and 
a ^-inch allowance to turn up to lock the edge of 
gutter to. For instance, if the deck strip is 2^ inches, 
and you have a 30-inch header which turns a ^-inch 
bead, cut the tin in 5-inch strips, and cut in with the 
snips }i of an inch deep in each end of each piece, 2 
inches from one edge, as shown at A, Fig. i. Notch 

Box Gutter Fig. 1. 



r 



^ ---- ---A ? 



the other two corners, being careful to take off corner 
enough to allow for a 34 -inch fold across the end and 
along the side also. 

Next fold both ends the same as for valley, i. e., in 
opposite directions, one up and one down, turning 
clear down so as to lock them together, and fold the 
edge C D up square, or a little more. Then straighten 
out the 2 inches of end folds which was previously cut, 



XXTH CENTURY SHEET xMETAL WORKER. 39 
as shown by dotted lines B A at each end of cut Y in 
Fig. I. Hammer these ends down pretty flat with the 
mallet, so they will slip into the header readily. Then 
bead the edge B B, turning the bead on the side oppo- 
site to the bend of edge C D. 

An end section of the finished- piece is shown in Fig. 
2, which clearly shows the bead turned down, the op- 
posite edge turned up, and the up fold of one end, 
but does not show the down fold of the other end. 

Get out enough of these pieces to cover the deck 
strip, and enough valley (14-inch is wide enough for 



o 



Pig. 2. 

most ordinary gutters) being careful that it is well 
soldered. 

Put on the bead first, by putting one in place, then 
slip the bead of the next over that, and pushing them 
together far enough to let the fold A C catch over the 
fold A D, and then pulling back till they lock together. 

Nail close to the fold C D, so the heads will be cov- 
ered when it is hammered down, and put an occasional 
slim nail through the bead into the edge of crown 
mould as shown at A in Fig. 3. 

When the bead is all in place, measure from bottom 
of gutter at B to a point about J4 inch above the turned 
up edge at C, Fig. 3. Take this measure at the low 
point of gutter, and again at the high point, and trans- 
fer these measurements to the edge of the strip of 
valley, and bend up with tongs or straight edge and 
mallet. Then measure the width of gutter B to D, at 



40 XXTH CENTURY SHEET METAL WORKER. 

both ends, as the width often varies as well as the 
depth, and bend square up. 

Next set the tin into the gutter and get into it with 
one knee, or one foot, to hold it down, and start the 
edge C over with tongs or plyers, and hammer it down 
to an angle, and then clinch it tight with cleating tongs 




Fig. 3. 

or plyers, and finish down flat with the mallet. 

Then, still keeping the weight in the gutter, bend 
the back at E down onto the roof boards, and put in 
an occasional nail if the roof is to be shingled, but if 
it is to be tinned, turn up the back edge at F and blind 
nail, thus leaving it ready to lock the roofing on. 

This same method of bead finish may also be used 
without gutter, if so desired. I have often put on 
porch roofs with this kind of finish. Using, however, 
full sheets instead of the narrow strips. 

Slit each end of the sheets, and, after folding the 
two ends and one side, straighten out the narrow part 
of the end folds, just as described, and turn the bead 
the same as shown on the narrow strips. 



XXTll CEX'IURV SIIF.ET METAL WORKER. 41 

In connection with the box c;ntter it might be well to 
mention my way of making the ends. Tinners differ 
in their manner of doing things, and I do not claim 
to have the only right way. But I mention these mat- 
ters, hoping to help some workman who has met with 
the same difificulties that have hindered me so many 
times. 

I usually cut the tin enough longer than the gutter 
to equal the greatest depth of both ends, and a little 
to spare. Then slash straight in at the ends, at each 
bend, B, D and E, about as far as the height of D E. 
Bend C B and D E in towards each other, and the 
bottom, BD, up. ^^rim off the surplus tin and solder 
the edges well. 

An end may be cut to fit and soldered in, but in most 
cases this is no advantage, and takes much longer. 
And in these days of competition, time is quite an 
object, and the workman who can do things quickly 
and well, stands a better show than the one who does 
them ever so well, but works slowly. 

Tlie ElUpse or Oval. 

A perfectly true ellipse can not be drawn with the 
dividers and two radii. But there are several methods 
of drawing them in this manner, which so nearly 
approximates the true ellipse as to answer the purpose 
for most tin shop work. 

A very accurate method, however, is by the string 
and nail process. Fig. i is drawn in this manner. 

Draw A B the length of the major axis and bi- 
secting it at right angles draw C D the length of the 
minor axis. With C or D as center and one-half the 



42 XXTH CENTURY SHEET METAL WORKER. 

major axis as radius, mark the points E and F on the 
major axis. Drive nails at E. F and C, and tie a 
string tightly around the three nails. Remove the nail 
at C and with a pencil or scriber draw the ellipse, 
keeping the string tight. 



/ 


-. \ 


/ 


"~\ 


1 


/ 




/ 

/ 




/ 


f 


/ 


V ' 


/ 




/ 




/ 




/ 1 




/ / 




/ 




/ 


\ « 


p / 



Fig. 1. 

If the pencil is held in an upright position and the 
string is not allowed to slip up or down on it, and does 
not stretch more in some directions than in others, the 
result will be a perfect ellipse. In fact, it is in strict 
accord with the scientific definition of an ellipse — "A 



XXTH CKNTURY SHEET METAL WORKER. 43 
figure bounded 1 y a curved line, every point of which 
is equally distant from two points within, called foci." 




In this figure, E and F are the foci, and the distance 
from any point in the curve to F plus the distance from 



44 XXTH CENTURY SHRET METAL WORKER. 

the same point to E is the same as the combined dis- 
tances from these two ])oints to any other point in the 
curve, and is just equal to the lenj::^th of the major 
axis. 

In Fig". 2 is shown a very near approximate to an 
elHpse, composed of arcs of circles, having three dif- 
ferent radii and eight centers, hence it is called the 
"eight centered oval." 

To draw an oval by this method, draw A B the 
length of major axis, and bisect it at right angles by 
C D indefinitely. Mark points O P on C D the length 
of minor axis. 

Now to determine the radii to be used, draw X Y 
and X Z, Fig. 3, forming any convenient angle at X. 
With X as center and radius equal to half the short 
axis strike the arc V W. With same center and radius 
half the long axis draw the arc S T. Connect W and 
S, and parallel to W S draw \' U and R T. Then 
X U w^ill be the radius to use for the arcs at the ex- 
tremities of the major axis, and X R will be the radius 
for the side arcs at the extremities of the minor axis. 
For the radius of the arcs to connect the side arcs 
with the end arcs take the length of the semi-minor 
axis plus half the difference between the semi-axes, 
which is (in Fig. 3) the distance X V plus half the 
distance V S, hence X O. 

On A B of Fig. 2 set oft" -\ E and B F, each equal 
to X U. And .\ G and B H each equal to X O. Lay 
off from O to D and from P to C, each equal to X R 
and from O to J and P to I each equal to X O. 

With C as center and radius C I draw the arc i 2, 



XXTH CENTURY SHEET METAL WORKER. 45 
and with D as center and same radius draw the arc 3 
4. With E and F as centers and radius E G or F H 
strike the arcs through G and H intersecting the arcs 
I 2 and 3 4 at the points i 3 and 2 4. Draw a hne 




FiG. 4. • 

through E from i to 5 equal in length to X Q, and 
from 3 to 6 same length, and the same through F 
from 2 to 7 and from 4 to 8. 

From C through i and 2 draw lines the length of 
X R, and from D through 3 and 4 same length, end- 
ing at 9, 10, II and 12. 



46 XXTH CENTURY SHEET METAL WORKER. 

With C as center and radius C P (or X R) draw 
the arc 9 10, and with D as center and same radius 
draw II 12. With E and F as centers and radius E A 
(or X U ) draw 5 6 and 7 8. Then with i, 2, 3 and 4 




B 
Pig, 5. 

respectively as centers and radius I to 5 (or X Q) 
draw the four connecting arcs 5 to 9, 7 to 10, 8 to 12 
and 6 to II. This completes the eight centered ellipse, 
which is a very near approach to the shape of that in 
Fig. I, constructed with the string and nails. 

Figures 4 and 5 are of the four centered kind, using 



XXTH CENTURY SHEET METAL WORKER. 47 
only two radii. Eitlier of these will answer very well 
for small articles. ¥\g. 4 is, however, slightly nearer 
to the perfect ellipse than Fig. 5. 

To draw Fig. 4 make A B the length of major axis, 
and bisect it with the indefinite line C D at right 
angles to it on which mark x x length of minor axis. 
From A set off the length of required minor axis, 
marked E, and divide E B into 4 equal spaces. With 
3 of these spaces, (which is ^ the difference of the 
two axes) as radius, and F as center, mark G and H 
and describe circles with radius A M or B G. Take 
the distance from F to the nearest ei\s:;e of one of the 
circles and set off from x x marking the points I and 
J. From I and J draw lines through H and G re- 
spectively, as J to I and 2. and I to 3 and 4. 

With I and J as centers and radius I to opposite x 
draw the arc 3 4. And with J as center and same 
radius strike the arc i 2, completing the figure. 

For Fig. 5, draw A 15 and C D, the length and 
width desired. From A set off the width, A to E, 
then E B is the difference of the axis. Take half this 
difference, which is E V, for radius, and with G as 
center strike the arc H I. Draw the chord H I and 
bisect it at J. With I as center and radius I J draw 
the arc J K. With G as center and radius G K mark 
L, M and N. Draw lines from L and N both ways 
through K and M, and use K, L, M and N respec- 
tively for the centers from which to draw the four 
arcs to form the oval. 

These four figures are all drawn to the same dimen- 
sions, i.e, the same lengths of axes, and the different 



48 XXTH CENTURY SHEET METAL WORKER. 

degrees of variation from the nearest perfect form 
(Fig. i) are readily detected. 

Oval Flaring: Pan. 

Having described several methods of drawing ellip- 
tical and oval figures, and knowing that many work- 
men have their own rules for drawing the oval, I will 
omit that part here, and give an easy short rule for 
pattern for the body of flaring oval pans. 

Around the corner of the square draw indefinitely 
ABC. Fig. I. From B mark D the perpendicular 
depth of pan desired. From D draw D E parallel to 
A B, and make the distance from D to E the same 
as the radius I x of the side arc of the oval, Fig. 4. On A 
B mark F as far from B as the side radius plus the 
required flare of one side of pan, i. e., make B F just 
once the flare longer than D E. Then draw from F 
a line through E, continued to intersect B C at C. The 
distance from C to E is the radius of curvature of the 
bottom of the portion of the body to fit a side arc (as 
I X 2) of the oval. 

Next, on D E mark e, the length of end radius of 
oval (A H of Fig. 4). and from B mark f the same 
distance plus the flare, and draw fee, which will be 
parallel to F E C, and gives the radii for end portion 
of body. 

Now draw a center line G H^ Fig. 2. and with H as 
center and radius C E of Fig. i. describe the arc I J 
equal in length to i x 2 of the oval, measured with a 
bent strip or by stepping with dividers. With same 
center and radius C F draw the arc K L limited by 
lines drawn from H through I and J. Then K I J L 



XXTH CENTURY SHEET METAL WORKER. 49 
is the pattern for one side of pan. No-.v we will sup- 
pose the body is to be made in two pieces, with the 




Fig,, 1. 



seams at the ends. To complete the pattern we must 
add half the end pattern to each end of K I J L. Set 



so XXTH CENTURY SHEET METAL WORKER, 
off from K and L. towards H, the distance c f of Fig. 
I, here marked h h and with these points as centers 
and radius c e draw tlie arcs I i and J j each equal in 
length to one-half the end arc of oval^ as A i or A 4 
of Fig. 4. From h and h draw lines through i and j 




to k and 1. With same centers and radius c f draw 
arcs K k and L 1. Add allowance for wire, burr and 
locks, and the pattern is complete for one-half the 
body. 

If the body is to be in four pieces, make lock allow- 



XXTH CENTURY SHEET METAL WORKER. 51 

ance at K I and L J, and draw the two end halves 
in one piece, and add locks to both ends of it. 

Figs. I and 2 are drawn to a smaller scale than the 
ovals in the other chapter, and the measurements do 
not exactly correspond with them. For this reason 
F'\g. 4 is here reproduced of a size and shape suitable 
to illustrate Figs, i and 2 of this chapter. 



0-- 




— i) 



Fig. 4. 

Above all things do not use C D and c D of Fig. i 
for radii, as is often done by some, they are not the 
correct radii, being only the perpendiculars of the 
triangles the hypothenuse of which are the true radii. 

Pan Corners. 

There are several ways of cutting a pan corner so 
that the folded corner will come up true under the 
wire. And there are many workmen who only guess 
at it, and make a poor corner in consequence. 

In this chapter I will mention three methods, by 



52 XXTH CENTURY SHEET METAL WORKER. 

any one of which the corner may be so quickly laid out 
that it would not be profitable to use guess work, and 
thev are all accurate methods. 




Fig. 1. 



The first is the: one I most often use, although I do 
not know that it is any better or quicker than either 
of the others. 

On a perfectly square corner of the sheet to be 
used, lay off the allowance for wire ABC Fig. i. 
Parallel to these lines and far enough in from them 
for the slant depth of the pan, make D E F. From 
the points G and E set off towards B the desired flare, 
one-half the difference between the size of the top and 
bottom. Draw lines from the points thus found at H 
and I, to J. 

Next place the handle of a bevel against the edge 
of sheet, and adjust the blade until it coincides with 



XXTH CENTURY SHEET METAL WORKER. 53 

the line H J. Then swing the bevel around till the 
handle is on H J as shown in Fig. 2, with the inner 
angle of blade and handle at H, and scribe along the 
blade from H to the center line J B. Reverse the 




FiS. 2. 



bevel, placing the handle on line I J, and scribe from 
I to the same point on center line as before. 

Cut across the wire allowance at any desired angle, 
or square in to H and I, then through on the lines 
drawn, being careful to cut accurately when the piece 
may be used for a pattern by which to cut the other 
three corners, when you have them located. To do 
this measure from H along line A B the distance re- 
quired for width of top, inside of wire. And from I 
along line B C the length of top, inside of wire. Then 
place the little corner pattern on with one of its 
straight edges coinciding with the edge of the iron, 



54 XXTH CENTURY SHEET METAL WORKER, 
and the point H or I at the point found by measure. 
Mark the cut line and along the farther edge of pat- 
tern which will give the point at which to square off 
the sheet. Square from both the corners thus found, 
which will locate the fourth corner. 





1 


3 




^" 


T/ 


*• 




Vo^^r' 


T- 


K0 


? 

Q 


r^ 




"P 


0^ 




^J 


Jf 

Fig. 3, 


J 


K 


D 





The second method is by means of rule or square, 
and dividers. 

Lay off A B C, D E and F G, and locate H and I 
the same as described in the first method. Then with 
dividers set at J, Fig. 3, strike a long arc, or semi- 
circle. Span dividers from intersection of arc with 
line B J to intersection with line H J and swing 
around to point X. Draw a line from J to X and the 
point where this line intersects the line of wire allow- 
ance is the right height from J for the center line B J, 



XXTH CENTURY SHEET METAL WORKER. 55 
because the line J X is in the position B J will occupy 
when folded around against end of pan. 

Span dividers from J to o and swing around and 
mark B J at o'. 

Scribe from H to o' and from I to o', and cut out, 

E 



Si 



Nb 1/ 


n 




\^^\ 


\f 




Ik 


Pig, 4, 
D 



p 



cutting wire allowance at any desired angle, thus com- 
pleting the corner. 

The third method is on nearly the same principle 
as the first, except that the angles are found by means 
of the dividers instead of a bevel. 

After laying ofif A B C, D E and F G, and locat- 
ing H and I as before, span dividers from H to a point 
nearly, but not quite to B. on line A B, and strike on 
arc downward as shown in Fig. 4. With dividers un- 



56 XXTH CENTURY SHEET METAL WORKER. 

changed set one foot at J and strike an arc cutting 
H J and G J at K and L. 

Then span dividers from K to L, and starting at M 
step off twice that distance (two steps) to N. Draw 
by the straight edge from H to N, and from I to the 
point of intersection with B J, and cut out as before. 

In the first method we obtained the angle of H J 
by means of the bevel and by applying this angle again 
we produced the line H N (or the line corresponding 
to H N) at twice that angle with the line A B, and 
in this case, by stepping twice the distance K to L on 
an equal arc, we produce H N at just twice the angle 
of H J. 

As before stated, the corner may be cut out and 
used as a pattern for the other three corners, but in 
practice I prefer to lay out all the corners first except 
the lines of cut, and then complete one, and use the 
piece for pattern for the others. Because the lineJ 
H J, B J and I J are needed as guides for making the 
bends when forming up. 

A Deflected Snap Bottom. 

A snap bottom may often be used on small articles 
of tinware, instead of a double seamed bottom, and 
given a deflection in the "setting down machine." 
Cups, dippers, small basins and other small vessels 
may be made in this manner, quickly and neatly. 

Burr the bottom of body out nearly as much as for 
a double steam, and perhaps just slightly wider. Not 
too wide, however. 

Cut and burr the bottom so it will po on pretty snug, 
and run it in the setting down machine, holding the 



XXTH CENTURY SHEET METAL WORKER. 57 
article up enough to begin to just start a deflect in the 
bottom, and continue to raise gradually until the seam 
is at an angle of about 45 degrees, as shown in the sec- 
tion of bottom underneath the cup, in drawing. 

With very little practice, and a good setting down 




Section of Bottom. 



—4 



machine, this can be done very quickly, and makes a 
neat job. 

A double seamed bottom can also be deflected in 
the setting down machine, if it is a very small seam, 
and pretty smoothly finished, and not too tight. If the 



58 XXTH CENTURY SHEET METAL WORKER. 

seam is small enough to allow of starting it between 
the wheels of the machine, and care is used in handling 
the work, quite a neat looking deflect may be made. 

Farnac* Pipe Boot by Trlsngulation. 

As triangulation is a more simple and accurate 
method of obtaining patterns for some of the more 
irregular and complicated shapes, this second chap- 
ter is given for the benefit of those unfamiliar with the 
process. And I believe, if the reader will carefully 
study this and the chapter on the "Transition Piece," 
he will be able to develop the pattern for almost any 
desired article, by this very useful and simple process. 

Figure i is a perspective view of a common shape 




Fig. 1. 

of boot for furnace pipe, and is a transition piece, or 
more strictly speaking, the body between the straight 
collars is a transition piece, and is the portion for 
which we will develop the pattern. 

This boot is to fit a round pipe at one end lo inches 
in diameter, and to fit a "riser" or wall pipe at the 
other 2x14 inches. 

In practice it is unnecessary to draw the perspec- 
tive. And even the elevations may be omitted, if the 
workman has the idea, or the picture of the article in 
his mind, and the work done entirely with the plan 



XXTH CENTURY SHEET METAE WORKER. SO 

shown at the bottom of Fig-. 2. the circle and the 
parallelogram. 

Space the circle into any desired nnmher of eqnal 
parts, here 10 are used. Construct a diagram of tri- 
angles as shown at the right of "side elevation." Make 




Pig. ' 2. 

the j)erpen(Iicular E P> equal to the vertical height of 
the body of the article, and the base exactly at right 
angles to it, and of indefinite length. With the divid- 
ers measure each of the distances from the corner D 



6o XXTH CENTURY SHEET METAL WORKER. 

to E, I. 2, 3, 4 and 5 and set each one as found, off 
to the right from E on tlie base Hne of the diagram of 
triangles, marking each one for future references. 
Then take the distances from X to 5, 6, 7, 8, 9 and 
10. being careful to number each one. 

Now to develop the pattern, draw the right angle 
BED, making B E equal to the vertical height (BE 
of the diagram of triangles) and E D equal to E D of 
the plan (one-half the length of one side of the par- 
allelogram) and with one pair of dividers take the 
distance from B to i on the D of T and place one 
foot at D on pattern, and with another pair of dividers 
set to one of the spaces on circle place one foot of 
these at B on pattern describe a short arc to intersect 
an arc made by the other spanned from D, thus lo- 
cating the point i of the irregular curve of pattern. 
Keep the one pair of dividers set the length of one 
of the spaces and continue in rotation, setting the other 
pair from B to 2 on the D of T and span from D to 
meet the space dividers at 2, and continue the meas- 
urements thus until 5 is located on the curve line of 
pattern. Then take the distance from 5-X from B 
on the D of T and span downward from 5 on the pat- 
tern and meet it with a measurement from D equal 
to D X on the plan (the width of the parallelogram)- 
Then proceed with the remaining distances the same 
as with the first quarter of the circle, except we span 
from X instead of D to locate 6, 7, 8, 9 and 10. 

It was necessary for us to take the measurement 
from 5 to X as well as from 5 to D on plan and trans- 



XXTH CENTURY SHEET METAL WORKER. 6i 
fcr it to the D of T in order to locate the point X of 
the pattern. 

Now to locate the point G of pattern take the dis- 
tance lo to G shown in "end elevation" and span it 
downward from lO on pattern and meet it with the 




Fig. 3. 



distance X G of plan (half the length of parallelo- 
gram) spanned out from X. Connect the points thus 
found by straight lines from D to X, from X to G and 
from G to lo, and by drawing a free hand curve 
through B, 1,2, 3, 4, 5, 6 7, 8. 9 and 10, which com- 
pletes one-half the pattern. The other half may be 
drawn in the same manner, or by cutting out this 
half and scribing around it. 

The end elevation was referred to once in the above 
description, and a measurement from that elevation 
was used in locating G on the pattern, but we could 
have located it without the end elevation, by measur- 
ing across from 10 to G on the plan and transferring 
the distance to the base line of the D of T, then 
from that point to B is equal to 10 G of the eleva- 
tion, and of the pattern as well. 



62 XXTH CENTURY SHEET ^lETAL WORKER. 

Of course, an allowance must be made all around 
this pattern, to lock the ends of pattern together, and 
to lock the collars on. 

Tee on a Tapered Pipe. 

For convenience in describing we will use definite 
dimensions- — viz.: A tapered pipe (frustrum of a 
cone) 8 inches in diameter at base, 3 inches at top and 
8 inches i)erpendicular height, about S^i inches slant 
height, intersected by a straight pipe 2 inches in 
diameter, at an angle of 30 degrees to the axis of the 
tapered pipe. 

To develop the patterns for the above descril^ed 
article : 

Draw a center line A B and with C on this line as 
center construct the plan of the tapered pipe, C(jn- 
sisting of a circle of 3 inches diameter surrounded by 
a concentric circle 8 inches in diameter. Then draw 
an 8-inch diameter through C at right angles to A B, 
and from the ends of this diameter extend dotted linos 
upward any convenient distance to the points D and 
E. Connect D and E by a straight line parallel to 
the diameter drawn in plan, and at right angles to 
A B, thus forming the base of an elevation of the 
article. 

On the center line 8 inches above the point X. 
where it intersects the base line D E, mark Y. and 
through L draw G F 3 inches long, being careful to 
make it just i>^ inches each side of Y and parallel to 
D E. Connect E F and D G and continue the lines 
until they meet on the center line at A. 

Next draw the 2-inch pipe projecting from the side 



XXTH CENTURY SHEET METAL WORKER. 63 

F F of elevation and at an angle of 30 degrees to the 
center line A B, represented by the straight lines 
H I J K. This completes the elevation. 

Now drop dotted lines from H and K down to the 




transverse diameter of plan, and using for center a 
point midway between these lines on this diameter, 
describe a 2-inch circle and space it into any number 
of equal spaces, here 12. From center C draw radial 
lines through tliese space points just to the outer 
circle (base of tapered pipe), and from tliose inter- 
sections above and including- the diameter line, draw 



64 XXTH CENTURY SHEET METAL WORKER. 

parallel dotted lines upward to D E, and radial lines 
from A to meet these on D E. 

Find the center of the line I J representing the up- 
per end of the 2-inch pipe, and draw a semi-circle 
upon it as shown, and space it into six equal spaces, 
and from these points draw parallel lines to intersect 
each in turn of the radial lines, and draw a free hand 
curve through the points of intersection, which gives 
us the true elevation view of the shape of the base of 
the small pipe, shown by the heavy curve line H to K. 

To develop the pattern for this pipe draw the 
stretchout ^Nl X O P equal to 12 of the spaces on the 
semi-circle I J and space it into 12 equal spaces as 
shown and placed exactly parallel with the pipe. Then 
draw lines at right angles to the pipe and stretchout, 
from the points of intersection on curve H K to inter- 
sect with the space lines on stretchout, and through 
these points of intersection draw the curve the same 
as in making an elbow pattern. 

To develop the pattern for the tapered pipe, set the 
dividers at A and with radius A D draw the arc O R 
and with radius A G the arc S T. Step off one-quar- 
ter of the large circle in plan into any desired number 
of equal spaces and, if only half the pattern is desired 
in a piece as here shown, step twice the number 
found in the quarter circle on the arc O R, and con- 
nect R T and O S by drawing radial lines towards A. 
This will then be the pattern for half the tapered pipe. 
If, however, it is desired to make the pattern in one 
piece, step off four times the number of spaces found 



XXTH CENTURY SHEET METAL WORKER. 65 
in the quarter circle of plan, onto the continued arc 
OR. 

To cut the opening in this pattern for the small pipe 
to fit, draw the radial line A U wherever desired — 
here shown in the middle of the half pattern — and 
from it space off each way the spaces obtained in plan 




by drawing the radial lines through the space points 
in small circle to the circumference of tlie base. The 
line A U of pattern is the same line as C L' in plan, 
hence we space on O R each way from U the same 
distances as shown in plan each side of U. Then 
draw radial lines from A to all these points on O R. 
Next draw parallel lines across the elevation from the 



66 XXTH CENTURY SHEET METAL WORKER. 

intersecting points on curve H K at right angles to 
A B and intersecting the side D G and with the di- 
viders draw curves from the points where the hori- 
zontal Hues meet D G, using A as center to intersect 
the radial lines drawn from A to O R, and through 
the points of intersection draw the irregular egg 
shaped oval which will be the shape of the opening. 

All locks and laps must be allowed outside of the 
pattern lines. 

To develop patterns for the same article by trian- 
gulation. 

Draw plan and elevation the 'same in outline as for 
projection, and the semi-circle T J on end of small 
pipe and space it the same as in the previous example. 
Drop dotted lines from the points H and K to the 
transverse diameter of plan and space the portion be- 
tween them into 6 equal spaces, and with C as center 
draw short concentric arcs through these space marks. 
Draw a dotted outline of the small pipe projecting as 
far as the point I in elevation and on its diameter 
X Y dfaw a semi-circle spacing it the same as the one 
in elevation. 

Draw lines from the semi-circle X Y to intersect the 
arcs and through the points of intersection draw the 
irregular curve as shown, which represents the top 
view of the small pipe intersecting the tapering pipe. 

Now through the intersections above the diameter 
draw 3 radial lines to the large circumference of plan 
and project lines from these points up to base line 
D E of elevation, and draw radial lines from A to 
meet them. Draw parallel lines from the semi-circle 



XXTII CENTURY SHEET METAL WORKER. 67 
I J to intersect the radial lines and mark the curve 
HK. 

Space one quarter of the large circle of plan into 
6 equal spaces, and make lines towards the center C 
and just to the small circumference, thus spacing the 
small circle into the same number of equal spaces as 
the large one. Number the points on the inner circle 

1 to 7. and those on the outer circle 8 to 14. Draw a 
diagonal line from i to 13 and set off its length on 
base line of elevation as shown from 14 to 13, then the 
distance from the center of the line F G and i. to the 
point marked 13 on the base line, will be the true 
length of the diagonal line i to 13. And the side 
G D or F E is the true length of i to 14. 2 to 13, etc. 

Now draw one side of pattern T R. the length of 
D G and mark one end i and the other 14. With a 
pair of dividers spanned to the length of the line i to 
13 in elevation set one point at i at the top end of 
the line T R. and with a second pair of dividers 
spanned one of the spaces of the large circle of plan, 
measure out from 14 at the lower end of the line T R 
and mark a short arc across one made by the dividers 
reaching from i, thus locating 13. Next take the dis- 
tance D G of elevation and with one foot of dividers 
at the newly found point 13 measure upward and 
locate 2 just the distance of one of the spaces of small 
circle out from i. It is a great convenience to have 
a third pair of dividers and keep them set to this dis- 
tance. And as i to 13, and D to G happen, in this 
instance, to be the same length, they can be used with- 
out change for both measurements. Now mark from 

2 to 12 measuring out from 13 with the dividers which 



68 XXTH CENTURY SHEET METAL WORKER. 

are set to the large circle spaces. Then from 12 to 3 
measuring out with those set to the short spaces, and 
so on until one-half, or if so desired, the whole pat- 
tern is completed. 

To get the opening for small pipe mark down on 
center line of pattern tl.^ distance from F to K (eleva- 
tion) and up from 8 the distance from E to H, and 
locate the center * where the side lines of pattern 
would cross, and using center * draw short arcs 
through the points marked. (T\y the way, if the work 
has been correctly done, the distance from O or R 
to * will be the same as from D or E to A of eleva- 
tion.) Next measure from point F to each in turn 
of the intersection points in curve between K and H 
and transfer them to the center line of pattern, meas- 
uring down from 7 each time, and draw an arc through 
each using * as center. Now take the distance from 
the center line, or rather the transverse diameter of 
plan, to the intersection point on each of the arcs and 
transfer each measurement to the corresponding arc 
on pattern, and through these points draw the curve 
for the opening. 

For pattern for small pipe, draw AI N the length 
required for circumference of pipe, in this case about 
6 5/16 inches, and M P and N O each equal to J K of 
elevation. Space M N into 12 equal spaces and draw 
the center line V W equal to H I, then draw lines 
from the space points parallel to V W of indefinite 
length but not longer than V W, and measure the 
distance from each of the points on the straight line 
I J to each corresponding point on the curved line H 
K and transfer each in turn to each side of the pattern. 



XXTH CENTURY SHEET METAL WORKER. 69 

These measurements may be verified by a diagonal 
measurement from each point as found, back to the 
last preceding" point as sliown by the diagonal dotted 
lines on both pattern and elevation. 

Fruit Jar Filler. 

A very convenient and ready selling fruit jar filler 
and dipper combined is here shown. 

The article is made in two pieces, which are shown 




in Figs. I and 2. Fig. i is the dipper portion, and 
should be raised slightly with the hammer. The edge 
A, of Fig. I, is to be double-seamed to the edge B, of 




Fig. 2, between the points marked e and e. The edges 
C and D are locked together forming the top side of 



70 XXTH CENTURY SHEET METAL WORKER. 

the funnel portion. And those edges marked a a a a 
are simply hemmed and flattened down in the burring 
machine. A wire makes the edge too thick to dip into 
the fruit. 

Fig. 3 shows the finished article, with the exception 
of the handle, which may be a dipper handle, soldered 
and well bossed, or a large saucepan handle riveted 
and soldered at the point marked E. 




This dipper and filler, when once tried, becomes a 
favorite with the ladies of the house, and will sell 
readily when its many uses become known in a neigh- 
borhood. 

Elbozi's, angles, tecs, roof saddles, chimney thiinhles, 
etc., all cut ill the same manner. 

We will first consider a square two-piece elbow, 
and a very convenient method of cutting it. By a 
square elbow I mean one of 90 degrees 

Lay cut the blank of sufficient length to make a 
pipe of the desired size, 18^8 inches for 6-inch pipe, or 
22 inches for 7-inch. Then allow as much on each 
side as will be required for locks, or lap if to rivet. 

We will now suppose we are to cut a 7-inch 90- 
degree elbow in two pieces. We will take a piece of 
sheet iron about 23 x 14 inches arid mark tlie lines 
XY and OZ 22 inches apart and parallel. This will 



XXTH CENTURY SHEET METAL WORKER. 71 
leave a half -inch for lock on each edge if we have 
previously cut it 27, inches long. 

On the line XY, about 3 i'.iches clown from X mark 
A: 3>< inches from A mark C, a' id 7 inches from A 
mark B. In the same manner, and at the same dis- 
tances mark on line OZ the points D, F and E. A and 
P,. and D and E are each 7 inches apart on their re- 



X 






















£ 


A 


1 


Ur^ 












-^ 


X 






/ 


r' 




\ 






^' 


5- 


C 




1.\ 


\ 


^ 










\ 


/, 


3 


:i 




— d- 

4)^ 


/I 


<^ 










/ 


\ 


^a 






— -^ 


A 






\ 






y 






^ 




B 


^i^XX 1 • 1 1^=^ 


F=^=-4 1 1 1 H 


r-^"*" ' 



E 



Elbows Fig. !• 

spective lines XY and QZ. This is tlie correct dis- 
tance, because the rise or backset of a 7-inch elbow 
is 7 inches, or just equal to the diameter of the pipe. 
This is the same in any other size, that is, the rise 
for any size of 90-degree two-piece elbow is just the 
diameter of the pipe. 

Now span the dividers 3J^ inches, the radius of the 
pipe, and with one foot at C, describe the semi-circle 
A to B. And with one foot at F describe one from 



72 XXTH CENTURY SHEET METAL WORKER. 

D to E. Next draw the center line from C to F, 
and with the dividers unchanged place one foot at 3 
where the center line crosses the semi-circle, and 
mark short arcs at i and 5. From A. same span, 
mark 2, and from B mark 4. Proceed the same at the 
other end of pattern, thus dividing each semi-circle 
into 6 equal spaces. 

Draw parallel lines from XY to OZ rnrough these 




Elbows Fig. 2, 

points, dividing the pattern into 6 unequal spaces, as 
chown in Fig. i of Elbows. 

Snace any one of the parallel lines, or the bottom 
edge of sheet into 12 equal spaces, and draw lines 
from the points perpendicularly, crossing the hori- 
zontal lines as shown, and draw a freehand line 
through the alternate points of intersection, from B 
to 5, to 8, to 7, to 10, to 5 and ending at E. This 



XXTH CENTURY SHEET METAL WORKER. 72> 
line is clearly shown by the heavy curved line in 
Fig. I. 

Cut on this line, and we have the two pieces A and 
B shown in Fig. 2, which, when formed up and locked 
will make a two-piece 90-degree elbow with one seam 
in the throat, and one on top. 




B 




Elbows Fig, 3» 

To make a roof saddle for the side of a half-pitch 
roof, cut on same line. 

But if for comb of roof, cut from B to 8, then down 
to 9, up to 10 and down to E, and use the lower piece 
shown by B of Fig. 3. The other piece resulting from 
this cut is a tee pattern, but without allowance for lap. 



74 XXTH CENTURY SHEET METAL WORKER. 

which may be added as desired, as shown bv dotted 
lines in A of Fig'. 3. It is, however, tlie true intersec- 
tion Hne of the Tee. 

A Fig. 3 is also the pattern for a stove-pipe thimlile 
to fit in a corner. And the other piece, B, is a thimble 
to fit the projecting corner of a chimney. 

Thus far we have only been working with angles 
of 90 degrees. To make patterns for other angles it 
is only required to get the rise of the miter line, and 
span the dividers to equal one-half of it, after which 
the process is the same. The semi-circles must be 
of a diameter equal to the required rise. 

To Find the Rise of Miter Line for 90 Degree Elbow of 
Any Number of Pieces. 

An easy manner of finding the rise of miter line for 
90 degree elbows of an\- number of pieces, is as fol- 
lows: 

Draw a square having each side equal to the diame- 
ter of the pipe, as shown by A, B, C and D of Figs. 
I, 3 and 5 of Miters. Draw the diagonal line from 
A to C, and with the dividers set the length of one 
side of the square, and one foot at C, draw a quadrant 
from B to D, and divide one half of it into i less equal 
spaces than the number of pieces desired in the elbow. 
Miters, Fig. i, shows method of getting the miter line 
for a three piece elbow. Fig. 3 a four piece, and Fig. 
5 a five piece. And Figs. 2, 4 and 6 show the pattern 
developed. 

In all cases the spacing on the quadrant must be 
done accurately, and the miter line extended through 



XXTH CKNTURY SHEET METAL WORKER. 75 
the point to the side of the square, and the true rise of 
the miter hne is the distance from B to the point 
where the miter Hne cuts the side of square, marked 
E in Fig. r. 

To prove that this mnhod gets the true rise, it is 
only necessary to refer to Fig. 7, which shows the out- 




I 



m 



Fig. 2. 




Fig. 3. 



Fig, 4. 





^ifi« 5« Fig. 6. 

Hne of the long, or outer, side of a three piece elbow 
drawn within the square, and drawn to a larger scale. 
This drawing also clearly shows the reason for spac- 
ing half the quadrant into one less than the number of 
pieces desired. .\ three piece elbow only has two 
miter lines. A four piece, three, etc. 



76 XXTH CENTURY SHEET METAL WORKER. 

The foregoing methods may also be appliKl to the 
cutting of patterns for angles of an}' shape ai well as 
90 degrees. It is only necessary to find th? rise of the 




Pig. 7. 
miter line, and draw the pattern as described by using 
semi-circles whose diameter is the rise required. 
Elbows of Less Than 90 Degrees, Called Angles. 

As before stated, these patterns may be obtained in 
the same manner as those we have been studying, after 
we obtain the rise of the miter line. 

We will now suppose we have found the required 
pitch of an angle to fit a certain place, by setting a 
bevel, or with two pieces of iron riveted together, or 
with two pieces of lath or shingle, as H and I of 
Fig. I. 

Draw AB and BC along the two blades of HI, and 
bisect the angle thus formed. This may be done by 
spanning the dividers an equal distance each way from 



XXTH CENTURY SHEET METAL WORKER. 17 

B and marking points as A and C, then with these 
points as centers and radius greater than A to B, strike 




rig. 2 

the intersecting arcs at D. Draw BF indefinitely 
through the intersection, and on this Hue locate a 



78 XXTH CENTURY SHEET METAL WORKER. 

point F just the diameter of the pipe distant from the 
nearest point on AB, which may be done by spanning 
the dividers to the diameter of pipe and striking the 
arc AC. Then draw EF at right angles to AB by 
means of one of the elementary rules for drawing a 
line from a given point to a given line, perpendicu- 
lar to the given line. 

When E is accurately located, BF will be the miter 




Fifi. 3. 



line, and the distance E to B is the required rise, and 
hence is the diameter of the semi-circles from which 
we develop the pattern. In other words, span the di- 
viders one-half the distance E to B for the radius, 
and proceed as in the development of elbows as before 
given. 

The angle shown in Fig. i, the complete elevation of 
which is shown in Fig. 2, is 45°. But it is not neces- 
sary that we should know the number of degrees. 

If, however, the required degrees are known, and 
we have a protractor, the process is even more simple. 

Draw AD, Fig. 3, equal in length to the diameter 



XXTH CENTURY SHEET METAL WORKER. 79 

of pipe, and by the protractor, draw DB at one-half 
the required angle. 

For instance, for a 30° angle, we draw DB at an 
angle of 15° to AD. Then one-half the distance A to 
B is the radius for our semi-circles. 




Pig, 4. 

The elevation of the finished 30° angle is shown in 

Fig. 4. 

To Draw Pattern for Any Regalar Tapering or Flaring Article 

The method here described will apply in drafting 
patterns for any of the round flaring and tapered arti- 
cles made in a tin shop, whether basins, pans, coffee 
pots or "Sibley stoves." Provided the bottom and top 
are parallel, and the sides a regular taper. 

Draw an elevation of the article, full size, as A, B, 



8o XXTH CENTURY SHEET METAL WORKER. 

C, D, of Fig. I, and extend the side lines until they 
meet, as at E. Then with E as center, and E D as 
radius, describe an arc cutting D and C, and if the 
pattern is to be in one piece, continue indefinitely to 
F. And with the same center, and radius E to A, 




Pig. !• 



strike an arc through A and B and extending in- 
definitely to G. 

Next draw a circle the size the large end of the 
finished article is to be, as Fig. 2, and divide it into 
quarters, as shown. (Or if more convenient, draw 
only a quarter circle.) Space the quarter circle into 



XXTH CENTURY SHEET METAL WORKER. 8i 

4, 5, or 6 spaces, or any convenient number, (here 5) 
as D to X, Fi,q-. 2, and step these onto the Hne D F, 
as shown from D to X in Fig. i. Then span dividers 
from D to X and step off three more times, 2, 3, F, 
thus locating- the point F, and making the arc D F 
almost equal in length to the circumference in Fig. 2. 

Draw an arc outside of, and parallel to D C F, as 
an allowance for burr or wire, according to whether 
the large end is to be the top or bottom of the finished 




Fig* 2. 

job. And another arc inside of, and parallel to A B G. 
Also, allow edges for lock or lap. parallel to A D, and 
G F, as shown by dotted lines in Fig. i. 

If it is desired to make the pattern in two pieces, use 
only twice the distance D X as shown at 2 in Fig. i. 
And if it is to be in three pieces get one-third the 
circle, Fig. 2, by stepping twice the radius, as O to P, 
and divide this into a number of equal spaces (here 7), 
which step on arc D F of Fig. i, from D to Y. 

It is a mistake sometimes made by tinners, to step 
6 times the radius of the required circle, on D F, to 
locate F, as this will make the pattern too short. While 



82 XXTH CENTURY SHEET METAL WORKER. 

6 times the radius just measures around inside its own 
circumference, yet it will not measure the same length 
of line when applied to the arc of a circle of a differ- 
ent size. This is illustrated in Fig. 3, where the circle 
shown is the same size as that in Fig. 2, and the radius 




Pig. 3. 

is shown stepped around it in six steps. Also, D F is 
made the same as DF in Fig. i, and the six steps 
shown only reaching to f, showing how much too 
short the pattern would be if measured in this manner. 
Even the method I have described is a little short 
of the true length but will be found near enough for 
most cases. If greater accuracy is desired I would 
recommend cutting a narrow strip of light sheet metal 
just the required length, and bending it to the proper 
curve, measure from D to locate F. 



XXTH CENTl'RV SHEET METAL WORKER. 83 

Some Convenient DimensioBi of Tinware. 

In the following dimensions the locks, burrs, wire 
locks, etc.. have all been allowed. That is for small 
neat seams. Don't put a pint cup together with a 
"stove pipe lock." 

There are two regular sizes of No. 8 wash boilers. 
The No. 8-18, and the small No. 8. 

For the No. 8-18 cut 3 pieces 14 x 19, or i piece 
56 X 14. 

For the No. 8 small cut 3 pieces 13^ x 18, or i 
piece 53-^ I3K'- 

For No. 9 boiler cut 3 pieces 14 x 20, or i piece 
59 X 14- 



Covered Buckets. 

2 quart . . .• 2 pieces 10 x 5^ 

3 quart . 2 pieces 10^ x 6 

4 quart 2 pieces 12 x 7 

6 quart 2 pieces 12^ x 8>^ 

8 quart 2 pieces 13^ x 9^ 

Flaring Pails. (Net Sizes ) 

2 quart, 6yi in. diam. top, 43^ diam. hot., 4 deep 
4 quart, 7>4 in. diam. top, 5 diam. bot., 5 '4 deep 
6 quart, 9I4 in. diam. top, 5>4 diam. bot., 6y2 deep 
8 quart, io'< in. diam. top, 6 diam. bot., 7J/< deep 
10 quart, UV2 in. diam. top, 7 diam. bot., 8 deep 
14 quart, 13 in. diam. top, 9 diam. bot., 9 deep 

Pans. (Net Sizes.) 

2 quart, 9 in. top, 6 in. bot., 3^)4 i"- fleep 
6 quart, 12^ in. top, 9 in. bot., 4 in. deep 



84 XXTH CENTURY SHEET METAL WORKER. 



10 quart. 14 in. top, 11 in. bot., 4^4 iii- deep 

14 quart, I5>:| in. top, 10 in. bot., 6 in. deep 

16 quart, 18 in. top, n iii. bot., 6^/ in. deep 

20 quart, 19^^ in. top, 13 in. bot., 8 in. deep 



Cans. (Cut to Bent Advantage.) 

To Hold. Size to Cut Sheet. 

1 gallon 7 X 21 inches 

2 gallons 10 X 25 inches 

3 gallons 103/2 X 30 inches 

4 gallons . 12 X 32 inches 

5 gallons 12 X 36 inches 

6 gallons 13 x 40 inches 

8 gallons 14 x 42 inches 

10 gallons 16 X 46 inches 

15 gallons 20 X48 inches 

20 gallons 20 X 57 inches 

25 gallons 22 X 60 inches 

40 gallons .26 X 70 inches 

50 gallons 26 X 76 inches 

75 gallons 30 X 86 inches 

fr>o gallons 36 X 96 inches 

To find the contents of cylindrical vessels. 

Multiply the square of the diameter in inches by the 
height in inches, and this product by the decimal .0034. 
The result will be the gallons, and decimal fraction of 
a gallon. 

This is a shorter method than finding the cubic 
inches and dividing by 231, and the result is exactly 
the same. 



XXTH CENTURY SHEET METAL WORKER. 85 
Practical Suggestions. 

To Clean Water Backs When Filled Up With Lime 
or Alkali. 

Pour slowly into the casting, muriatic (hydro- 
chloric) acid. 

This must be done carefully, as it will boil over and 
waste the acid unless care is taken. 

When the lime has all been removed, wash thor- 
oughly, and replace. 

To Cut Heavy Iron With the Stock Shears. 

When very heav\- iron is to be cut by hand, it will 
often be found a great help to turn the shears wrong 
side up and slip a piece of i-inch gas pipe, or larger if 
necessary, onto the tang, thus making a long leverage, 
and the pipe stands so nearly perpendicular that the 
workman can stand almost erect, and yet has a good 
leverage on the work. 

To Lock the Edges of a Pitched Cover, or Can Top. 

Often when making a cover or can top with only 
a slight pitch, it is desirable to lock the seam, but dif- 
ficult to do so in the folder. Try sli])ping each edge 
in the slot of the rod of gutter header, and turning 
the rod just enough to break the aV^c up a little more 
than sciuare, when the seam may be grooved down 
ver}' nicely. 

Teiitporarx Handles for Soldering Coppers. 

These may l)e (|uickly made by wrapping around 
the shank several thicknesses of asbestos paper. Draw 
it snug with a wire, and it will be found to answer 
the purpose very well, 



86 XXTH CENTURY SHEET METAL WORKER. 

To Tin Black Iron Rivets, or Other Small Articles. 

Put them in a bowl of raw acid (hydrochloric) until 
the black scale is well eaten off. Rinse with water 
and place in "killed" acid ; i. e., acid which has had 
all the zinc it will eat, and then without rinsing, drop 
into a pot of melted solder. Remove with a strainer. 



'V^/^T T cannot afford to place your 

^ ^^ vJ order for Stoves or Ranges 

of any kind without writing to the 

MONITOR STOVE 
AND RANGE CO. 

CINCINNATI 
FOR THEIR NEW CATALOG 

Makers of the 

MONITOR RADIATOR 

The Greatest and Best Hard Coal 
Base Burner 

Stoves and Ranges for all kinds of fuel 

MIONITOR 

STOVES & RANGES 



The Sheet Metal Worker With Ambition 
To Get Ahead Needs 

THE AMERICAN ARTISAN 

AND HARDWARE RECORD 
In His Business 

PUBLISHED EVERY SATURDAY 



Slieet metal workers, tinners and roofers wlio knf)\v, 
consider it the most authoritative and valuable pul)li<a- 
tion devoted to their interests — 

IT IS AND WILL CONTINUE TO BE 

Each issue contains one or more tinshop proljlems 
prepared and edited by experts. 

Each issue contains a fund of practical and instructi\e 
articles relating to the sheet metal industry. 

Subscribers are always at liberty to submit tinshop 
problems which puzzle them. In fact when we say that 
no publication even attempts to prepare as interesting or 
valuable a department for the sheet metal worker, we 
speak the truth. If you want the most news, tlie freshest 
news, the most instructive illustrated articles by the best 
authorities on Sheet Metal Work, Cornice Work, Tin 
Roofing. Furnace Installation, etc., 

THE AMERICAN ARTISAN 
is your trade paper. 

Subscribe To=day and Take Advantage of Our Special Offer 
Subscription Price, $2.00 A Year, 52 Issues. 



DANIEL STERN, 

Publisher and Proprietor, 

355 Dearborn St., CHICAGO 



Books by Mail 

D*TTCDMc''\'^ position to supply Teclinical BOOKS and 
PATTERNS ot all characters, at lowest prices 
« .**."«,''';*' ii'^l^i^'^'^ ^''C' most staiuianl works on Sheet 
>1etal Work, Heating and Ventilation, Plumbing and Drain= 
age. Advertising and the Workshop. 

Some Books and Patterns for the 
Sheet Metal Worker 

100 TINNERS' PATTERNS -Full sized patterns tor 
complete hne ot tniware— on lieavy manila i)aper ready 
tor use— nowhere can so complete a set be obtained a't 
the very Iom- price of ^1 ^^^ 

Gray's PERFECT ELBOW PATTERNS — absolutelv 
on'^'r^% ro'J'' -°" <^0 Pattt-rns 2, 8. 4, T, pieces) $1.50 
20 to 40" (SO patterns 5, 6, 7, 8 pieces) | so 

C'oinplete set of 1" to 4()" (2 to S pieces, 160 patterns) 
with angle chart 3 qq 

(hay's PERFECT SKYLIGHT PATTERNS -for sinHe 
pitch, hip and gal)le skyliglits. "" 

24" bar::;: ;:;::: ::::;;:::::: '^aH 

. CORNICE WORK /VlANUAL-240 pages (]S4'engn; v- 
mg.s) of important information for cornice worker $3.50 

TIN, SHEET IRON and COPPER PLATE WORKER 
''•X,,^^- •^- '^'""'' ''qiially valual)le for beginner and 
skilled artisan S;^ SO 

TINNERS' HELPER and PATTERN BOOK by II K 
Vosburgh — valuable rules, diagrams and tabl(\s— p,„ke1 
edition «1 00 

SHEET METAL WORKERS' QUIDE-with rulcs.md 
ihagrams for describing most useful patterns ordinarily 
used— al.so chapter on Sheet Metal Work, soldering and 
geometry «q ^q 

MANUAL OF RECEIPTS-' 241 pages', 1718 usefulre- 

ceipts tor the worksliop $3 SO 

Send for our complete list and prices. 
We prepay express on all orders. 
No books exchanged. 

DANIFI ^TFPIM 353-357 Dearborn St. 
1-^.n.l lULiLi O I ILiIxl^ CHICAGO, ILLINOIS 



29 \^IQ 



100 TINNERS' PATTERNS 

THE AMERICAN ARTISAN FULL SIZE PATTERNS 

Comprise patterns for a full line of tinware, in numerous sizes, square and round 
elbows, cut-offs, etc. These full size patterns, numbering upward 100, are printed 
on inanila paper, from which they are readily transferred fo heavy sheets and 
cut out ready for use. The list contains the following patterns; 
Tea Steeper Fourteeii-quart Milk Pail Breast 

Two-pint Tea Pot Two-inch Four-piece Round Elbow 
Three-pint Tea Pot Three-inch Four-piece Round Elbow 
Four-pint Tea Pot Four-inch Four-piece Round Elbow 
Five-pint Tea Pot Five-inch Four-piece Round Elbow 
One-quart Coffee Pot Five-and-a-half-inch Round Elbow 

Two-quart Coffee Pot Six-and-a-half-inch Round Elbow 

Three-quart Coffee Pot Seven-and-a-half-inch Round Elbow 
Small Grocers' Scoop 
Medium Grocers' Scoop 
Large Grocers' Scoop 



Four-quart Coffee Pot 
Five-quart Coffee Pot 
No. 1 Coffee Boiler 
No. 2 Coffee Boiler 
No. 3 Coffee Boiler 
Lamp Filler 
One-Pint Dipper 
One-quart Dipper 
Two-quart Dipper 
Four-quart Flaring Pail 
Six-quart Flaring Pail 
Eight-quart Flaring I'ail 
Ten-quart Flaring Pail 
Twelve-quart Flaring Pail 
Fourteen-quart Flaring Pai 
Ten-quart Dish Pan 
Twelve-quart Dish Pan 
Fourteen-quart Dish Pan 
Sixteen-quart Dish Pai\ 
Dinner Bucket 
I'^ive-inch T-Joint 
Six-inch T-Joint 
Eave Trough Mitre .Joint 
"Snap" 2-inch Conductor Elbow 
Cullender 
Two-inch Square Elbow 
Two-and-a-half inch Square Elbow 
Three-and-a-half-inch Square Elbow 
Four-and-a-half-inch Square Elliow 
Five-and-a-half-inch Square Elbow 
Six-and-a-half-inch Square Elbow 
Seven-and-a-half-inch Square Elbow 
One-pint Funnel 
Two-pint Funnel 
Three-jiint Funnel 
Four-pint Funnel 
Small Milk Strainer 
f^arge Milk Strainer 
Ten-(iuavt Milk Pail Breast 



Apple Corer 
Oval Foot Bath 
Oval Pudding Pan 
Half-gallon Can Breast 
One-gallon Can Breast 
Two-gallon Can Breast 
Three-gallon Can Breast 
Half-i)int Measure 
One-pint Measiue 
One-quart Measure 
Half-gallon Measure 
One-i)int Basin 
T wo-pint Basin 
Three-pint Basin 
Four-T)int Pan 
Six-quart pan 
Ten-(iuart Pan 
Small Cuke Pan 
Medium Cake I'an 
Large Cake Pan 
Small Wash Basin 
Large Wash Basin 
Sprinkler Breast 
Four-gallon Churn 
Five-gallon Churn 
Small Dust Pan 
Large Dust Pan 
Five Sizes Funnel Patrns. 
Oval Dinner Bucket 
Rain Water Cut-off 
No. 7 Boiler Cover 
No. 8 Boiler Cover 
No. 9 Boiler Cover 
No. 7 Boiler Bottoms 
No. 8 Boiler Bottoms 
No. 9 Boiler Bottoms 



THE AMERICAN ARTISAN full size patterns are a great convenience, and in no 

other way can they be obtained at so small a cost. Price, sent postpaid for the 

FULL SET OF 100 PATTERNS $1.00 

355 DEARBORN ST. 
CHICAGO, ILL. 



DANIEL STERN, 



REGISTERS and 

VENTILATORS 



» 



«■«■■■■■■■■ 
■■BBBBBBBHH 




CAST IRON 



or 



SEMI-STEEL 



or 



WROUGHT 
STEEL 



500,000 in Stock 



lY MFG. CO. 

One copy del. to Cat. Div. ) boston 



9tr:: 29 1910 



